Flight delays after Manchester Airport check-in fails
Hundreds of passengers had to wait for several hours at Manchester Airport because of a "technical failure" with the check-in system.
A total of 12 Thomas Cook flights were affected after staff had to switch to a manual check-in system, leading to delays. A number of other airlines also experienced problems.
Two flights at East Midlands Airport were also delayed.
Thomas Cook said all affected flights had now departed.
'Shouting and arguing'
A spokesperson for Thomas Cook said: "We're very sorry for the frustration caused to our customers at Manchester Airport check-in this morning.
"Our system is back up and running and we're working hard to catch up and get our customers on holiday as soon as possible."
It appeared "an issue with overnight maintenance" was to blame, said the spokesperson.
Dannii Martin, from Manchester, queued for more than three hours to check-in with her husband and seven-month-old daughter. They were due to fly to Bourgas in Bulgaria at 05:40 BST.
She said: "At check-in we were told so many different things and no-one could agree. Passengers were shouting at each other and arguing, people pushing in.
"Such a nightmare. Sat in [the] plane now, and apparently everyone has checked in, but don't know when we will take off."
She earlier tweeted Thomas Cook: "All systems down, manual check in so taking 20 mins per party. Got through after over 3 hours of queuing...
"Get to gate, an hour and 20 after our flight is meant to take off and no-one is here....Half the plane is still trying to check in, no updates on screen, no staff anywhere. Nothing."
Another passenger said: "Absolute ridiculous situation with @ThomasCookUK at Manchester airport! Systems are down complete and utter mayhem!! #no backup"
"Crazy queues," another added.
Manchester Airport earlier apologised and said: "Due to a technical issue this morning several airlines are having to check in passengers manually, which can take longer than normal."